1. Field of the Invention
The present invention is directed to a semiconductor chip with a membrane resting on metallic supports.
2. Description of the Related Art
Particularly in the manufacture of sensors and actuators, it is often required in semiconductor technology to produce a layer-like structure free above a substrate. Such a structure can be utilized, for example, as a membrane for pressure sensors, as a closure layer of a cavity or as an upper cooperating electrode for capacitative sensors or actuators. A thin aluminum layer, for example, as applied in the course of a CMOS process as a metallization level can be employed for such a membrane. Such a metal layer yields an electrically conductive membrane that, after the removal of the material situated thereunder, can serve, for example, as a cooperating electrode or as a pressure membrane for capacitative measurement. As a result of the mechanical stability, such a metal layer can also be advantageously employed when a cavity, in which a micromechanical elements moves, is to be covered toward the outside, such as, for example, given the component disclosed in German Patent Application P 19509868. A high, thermally caused tensile stress that deteriorates the mechanical stability of a membrane layer that is not supported surface-wide usually occurs in the metallization.